Electric signaling



(No Model.) 2 Sheets- Sheet 1. F. G. PRATT.

ELECTRIC SIGNALING.

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(No Model.) 2 Sheets-Sheet 2. F. G. PRATT. ELEOTRIG SIGNALING.

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FRANK G. PRATT, OF REVERE, MASSACHUSETTS, ASSIGNOR TO THE UNION SXVITOIIAND SIGNAL COMPANY, OF SIVISSVALE, PENNSYLVANIA.

ELECTRIC SIGNALING.

SPECIFICATION forming part of Letters Patent No. 552,776, dated January'7, 1896.

Application filed August 20, 1894. Serial No. 520,799- (No model.)

To all whom it may concern:

Be it known that I, FRANK G. PRATT, a citizen of the UnitedStates,residing at Revere, in the county of Suffolk and State of Massa-5 chusetts, have invented or discovered certain new and usefulImprovements in Electric Signaling, of which improvements the followingis a specification.

The invention described herein relates to I certain improvements inelectric signaling, and has for its object such an arrangement of relaysand their circuits as to require the dos ing of the circuits in acertain. definite predetermined order, before the signal-circuit propercan be closed so as to clear the signal after it has been shifted todanger. I

In general terms the invention consists i such arrangement of the relaysand circuits that the armatures of the former will, when released by thebreaking of the circuits, as sume an interlocking relation to eachother, thereby requiring the closing of the circuits of the relays in acertain predetermined order and consequent movements of the armatures,before the signal-circuit can be closed.

In the accompanying drawings, forming a part of this specification,Figure 1 shows one arrangement of the relays and armatures and theseveral circuits employed, and Fig. 2 3 shows a second arrangement ofthe same.

In the practice of my invention the relays 1, 2, and 3 are so arrangedthat the armatures and 6 are at right angles, or approximately so, tothe armature 4. The free end of the armature 5 extends over the end ofthe armature 4, so as to be engaged therewith when 'the relays 1 and 2are demagnetized and to drop behind the armature 4 when the latter isdrawn toward its magnet, and therebypre- 4 vent a return of the armature4 against the contact-point 7, until the armature 5 is drawn to itsmagnet. The magnet 3 with its armature 6 is so arranged with referenceto the armature 4 that if the magnet is demagnetized subsequent to thedemagnetization of magnet 1 and the consequent movement of the armature4 against the back contact-point '7, the free end of the armature 6 willdrop upon the block 8 of insulating material se- 50 cured to thearmature 4. If the magnet 1 should be excited while the magnet 3 isdemagnetized, the block 8 will be drawn away from the armature 6, whichwill thereupon be drawn against the back-stop 9, and while in suchposition will prevent a return movement of the armature 4 against thecontactpoint 7, if the magnet 1 should be demagnetized.

At suitable intervals along the line of track A are placed suitabledevices 10, 11, 12, and 13, such as are well known in the art andadapted to be operated by the passage of trains along the track A, tomake or break electric circuits, as hereinafter described for theoperation of the signals B and C.

The circuit for the magnet or relay 1 is formed by wire 14 connected toone pole of main. batteryX,wire 15, binding-post 16, magnet 1,binding-post 1'7, wire 18, movable member 19 of track-instrument 10,contact-point 20, common wire 21, and wire 22, connected to oppositepole of main battery. The circuit of magnet or relay 3 is formed bywires 14 and 15, branch wire 23, binding-post 24, magnet 3, wire 25,magnet 50, wire 26, movable member 27 of track-instrument 12,contact-point 28, common wire 21, wire 22, and main battery.

The circuit of magnet or relay 2 is formed by wire 14, binding-post 29,magnet 2, binding-post 30, wire 31, contact-point 32, pin 33, carried bybut insulated from armature 5, conducting-strip 34, wire 35,contactpoint 36, armature 37 of magnet 50, wire 38, supplemental batteryY, wire 39, movable member 40 of track-instrument 11, contact-point 41,common wire 21, wire 22 and main battery. The circuit for thesignal B isformed by the wires 14 and 15, branch wire'42, armature 4, contactpoint7 wire 43, contact point 44, spring 45, an armature 5 having the springattached thereto, wire 46, signal B, common wire 21, wire 22 and mainbattery.

It will be observed that the circuit through the magnet or relay 2 isnormally closed and the circuit through the magnet or relay 1 isnormally open, thereby maintaining the circuit through the signal Bclosed and the sig nal at safety. As a train passes over thetrack-instrument 10, it will so shift the movable member 19 thereof asto close the circuit through the magnet 1, causing said. magnet toattract the armature 4, thereby breaking the circuit through the signalat the contactpoint 7, and causing the signal to go to danger. Themovement of the armature 4 toward its magnet moves the block 3 away fromthe free end of the armature 6, permitting the armature to drop underthe block 8 against the stop 9, the circuit of the magnet 3 beingnormally open. Vhile the armature 6 is in this position, the armature 4cannot return into contact with the point 7, to close thesignal-circuit, even if the circuit through the magnet 1 be again brokenby the passage of the train from off the track-instrument 10, until thecircuit through magnet 3 be closed,so that its armature 6 will beshifted out of line with the block 8 on armature 4. The circuit throughmagnet 3 will remain open until the train reaches track-instrument 12 inthe circuit of magnet 3. The operation of this instrument by the traincloses the circuit through magnet 3, thereby causing such a movement ofits armature as will permit the armature 4 to drop onto contact 7 andclose the signal-circuit at that point. It is not desirable, however, toclear signal B until after the train has passed some distance into thesection next adjacent to that controlled by signal B, or in other wordssome distance beyond signal 0, which is arranged near instrument 12. Inorderto provide for holding the signal B at danger until the train haspassed a sufficient distance beyond O, the track-instrument 11 isarranged between the signals 13 and C. The operation of this instrumentby the train breaks the circuit through the magnet 2, and the consequentmovement of its armature not only breaks the signal-circuit at contact44, but also breaks the circuit of magnet 2 by the movement of thespring 34 away from the contact-point 32, so that the restoration of theinstrument 11 to normal condition on the passage of the train off of itwill not close the circuit through the magnet 2. As long as the circuitthrough the magnet 2 is broken, and its armature held against itsback-stop by its retracting-spring, the signal-circuit will remainbroken at 44.

The magnet 2 is included in the overlapcircuit consisting of battery X,wire 14, magnet 2, wire 47, movable member 48 of trackinstrument 13,contact-point 49, common wire 21, and wire 22 to battery. As a trainpasses over this instrument 13 it closes the overlapcircuit throughmagnet 2, causing it to attract its armature, by whose movement thesignal-circuit is completed at 44 and the main circuit of the magnet 2at 32, so that said magnet will remain excited after'the overlapcircuithas been broken by the return of instrument 13 to normal position on thepassage of the train off of it.

On some roads having the block system the rules permit a train, afterwaiting a certain time, to run past a signal, even if at danger; but thetrain must run under control. I11 such cases provision must be made toprevent the removal of the overlap protection of the second train. Inthe arrangement shown in Fig. 2, the first train having passed overinstruments 10, 11, and 12 has so operated the devices as to requireonly the operation of instrument 13 to clear the signal. The entrance ofa second train into the block and its passage over trackinstruments 10and 11, while the first train is between track-instruments 12 and 13,would, by closing the circuit of magnet 1 at 10, break thesignal-circuit by movement of armature 4 away from contact 7, and saidarmature would be held away from said contact by the automatic action ofarmature 6. The operation of instrument 11 by the second train would nothave any effect, as the circuit of magnet 2 had already been broken bythe first train. If while the second train is between instruments 11 and12 the first train should move on over instrument 13, the overlapcircuitof magnet 2 would be closed and the consequent movement of armature 5would close the main circuit of magnet 2 and the signal-circuit at 44,so that it only remains to close the circuit through magnet 3 to soshift its armature 6 as to permit armature 4 to drop onto contact 7 toclose the signal-circuit. net 3 would be effected by the passage of thesecond train over instrument 12.

It will be readily understood from the foregoing that as soon as thefirst train has passed track-instrument 13 and the second train haspassed instrument 12 the signal 13 will be cleared, and a followingtrain will not have any indication of the presence of a train betweeninstruments 12 and 13.

In order to prevent such a break in the proper protection of trains onroads using permissive blocking, a make-and-break device controlled bytrack-instrument 12 is introduced into the circuit of magnet 2. A formof such device is shown in Fig. 2, and consists of the armature 37 andcontact 36 of magnet 50, which is included in the circuit of magnet 3and controlled by track-instrument 12. If in using this arrangement thefirst train should pass over instrument 13, closing the circuit ofmagnet 2, as stated, the subsequent operation of track-instrument 12 bythe second train will close the circuit through the magnets 3 and 50,thereby so shifting the armature 6 as to permit the armature 4 to droponto contact 7, and also the armature 37, so as to break the circuitthrough the magnet 2, by the movement of whose armature thesignal-circuit is again broken at 44, and cannot be closed until thesecond train passes over instrument 13, thereby closing theoverlapcircuit through magnet 2.

In the arrangement shown in Fig. 1 the magnet 50, its armature and thecircuits connected therewith are omitted, and the circuit fromtrack-instrument 11 is formed-by movable member 40 of said instrument,wire 39, supplemental battery Y, wire 35, conductingstrip 34, pin 33,contact-pin 32, wire 31, binding-post 30, magnet 2, binding-post 29,wire This closin of circuit of 1n a 14, main battery X, Wire 22, mainWire 21 and contact-point 41. The circuit from track-instrument 12passes directly by wire 26 to one pole of magnet 3, in lieu of passingthrough magnet 50, as in the arrangement shown in Fig. 2. With theexceptions noted, the circuits shown in Fig. 1 are the same as thoseshown in Fig. 2.

In order to maintain overlap protection for a second train passingsignal B before the preceding train has passed track-instrument 13, ashort or shunt circuit around magnet 2 is provided. This shunt-circuit,starting from main battery X, consists of wire 14, bindingpost 29, Wire51, armature 6 of magnet 3, front contact 52, wire 53, binding-post 30,wire 31, contact-point 32, pin 33, conducting-strip 34, wire 35,supplemental battery Y, Wire 39, movable member 40 of track-instrument11, contact-pin 41, main wire 21 and wire 22 to main battery.

The operation of the shunt-circuit for the protection of a second trainpassing beyond track-instruments 10 and 11 before the preceding trainhas passed track-instrument 13 is the same as hereinbefore described-as,for example, the first train having passed over instruments 10, 11, and12 has set the signal at danger, and has so shifted the different partsof the apparatus that its passage over the instrument 13 will clear thesignal. Before the first train passes over instrument 13 a second trainenters the block and passes over instruments 10 and 11, therebyproducing a second break in the signal-circuit at contact-point 7 beforethe break at contact 44 has been closed. While the second train isbetween instruments 11 and 12, the first train passing over instrument1.3 closes the break in the signal-circuit at 44, so that the shiftingof the armature 6 out of line with the block 8 on armature 4, due to thepassage of the second train over instrument 12, permits the armature 4to drop and close the signalcircuit at contact-point? The closing of thesignal-circuit is prevented or the signal-circuit is immediately brokenby closing the shunt-circuit around magnet 2 by the same movement of thearmature 6 that releases the armature 4, as described. The closing ofthe shunt-circuit cuts out magnet 2, so that its armature will beshifted away from contact 44, breaking the signal-circuit at that point.As soon as the second train passes off of instrument 12, theshunt-circuit will be broken, so that the operation of instrument 13 bythe train will close the circuit through magnet 2, and thereby effectinga closure of the signalcircuit at 44 unless a third train has enteredthe block under time allowance.

It will be readily understood by those skilled in the art that anynumber of trains may follow each other through the block under timeallowance, and that each train will have overlap protection.

In case the main battery X should be shortoircuited, so that the magnet2 would be practically demagnetized, the successive and orderlyoperation of the several trackinstruments would be necessary after thefault had been corrected to clear signal B were it not for thesupplementary battery Y. This battery is so arranged in the circuit ofthe mag? net 2 as to reinforce the main battery in the orderly operationof the system and in case of a short circuit of the main battery tomaintain the magnet 2 in an excited condition, so that as soon as thefault is corrected the normal operation of the system can be renewed.

I claim herein as my invention- 1. In a railway signaling system, thecombination of a signal circuit, a magnet having its armature and acontact point included in the signal circuit, a make and break mechanismincluded in the circuit of said magnet and controlled by the passage ofa train, a make and break mechanism in the signal circuit, a relaycontrolling said make and break mechanism, a circuit for the magnet ofsaid relay including as a part thereof the armature and a contact pointof the relay, and a make and break mechanism included in said relaycircuit and controlled by the passage of a train, substantially as setforth.

2. In a railway signaling system, the combination of a signal circuit, amagnet having its armature and a contact point included in the signalcircuit, a make and break mechanism included in the circuit of saidmagnet and controlled by the passage of a train, a make and breakmechanism in the signal circuit, a relay controlling said make and breakmechanism, a circuit for the magnet of said relay including as a partthereof the armature and contact point ofthe relay, a make and breakmechanism included in said relay circuit and controlled by the passageof a train, and an overlap circuit including the magnet of the relay,and a make and break mechanism included in the overlap circuit andcontrolled by the passage of a train, substantially as set forth.

3. In a railway signaling system, the combination of a signal circuit, amake and break mechanism included in said circuit, a magnet controllingsaid make and break mechanism, a make and break mechanism included inthe circuit of said magnet and controlled by the passage of a train, alock for controlling the make and break mechanism of the signal circuit,a magnet controlling said lock, a circuit for said magnet includingtherein a make and break mechanism controlled by the passage of a train,a second make and break mechanism in the signal circuit (as at 44), arelay controlling said make and break mechanism, a circuit for themagnet of said relay including as a part thereof, a make and breakmechanism controlled by the armature of the relay, a make and breakmechanism (as at 11) included in the circuit of the relay and controlledby the passage of a train, an overlap circuit including the magnet ofthe relay, a make and break mechanism included in the overlap circuitand controlled by the passage of a train, and a make and break mechanismat 30) in the relay circuit and operative simultaneously with the makeand break mechanism controlling the locking magnet, substantially as setforth.

i. In a railway signaling system, the combination of a signalingcircuit, a series of two or more make and break mechanismsincluded insaid signal circuit and arranged to operate in a certain predeterminedorder to effect a restoration of the signal circuit and a series oftrack instruments for operating the make and break mechanisms in suchpredetermined order, substantially as set forth.

5. In a railway signaling system, the combination of a signalingcircuit, a series of two or more make and break mechanisms in saidsignaling circuit, electromagnets controlling the make and breakmechanisms, a series of track instruments included in the circuits ofsaid magnets and arranged to effect the operation of the make and breakmechanisms in a certain predetermined order, substantially as set forth.

0. In a railway signaling system, the combination of a signalingcircuit, a series of two or more make and break mechanisms included inthe signal circuit, electroniagnets controlling the make and breakmechanisms in a circuitin a predetermined order, a series of trackinstruments included in the circuits of said magnets, one of said trackinstruments so 0011- trolling the circuits of two of the magnets, thatone Will be demagnetized simultaneous with the completion of the circuitof the other magnet, substantially as set forth.

In testimony whereof I have hereunto set my hand.

FRANK G. PRATT.

Witnesses LLOYD BRIGGS, JOHN V. YOUNG.

